Maintaining genetic diversity is important to make sure all kiwi species and taxa survive.
Genetic research has lead to some exciting discoveries. In 1995, the tokoeka was found to be a separate species from brown kiwi, and in 2003, rowi was also recognised as a separate species from brown kiwi.
The five species of kiwi now recognised – brown kiwi, rowi, tokoeka, great spotted kiwi and little spotted kiwi – are generally well known. What is sometimes not known is that within a species of kiwi, there may still be genetic differences, which have often evolved as a result of geographic isolation. Where these differences are deemed significant, but not great enough to define a different species, we have what are called taxa.
For North Island brown kiwi, there are four different taxa: Northland brown kiwi, Coromandel brown kiwi, Western brown kiwi and Eastern brown kiwi. Each of these taxa have evolved slightly differently to adapt to things like the climate, food resources and geographical features.
The aim of genetics research
Research into kiwi genetics aims to make sure managed kiwi populations maintain good levels of genetic diversity. For example, by carefully selecting which birds to move around during translocations and as part of Operation Nest Egg projects.
Genetic bottlenecks may have naturally occurred in the past, reducing the genetic diversity within a population and increasing its probability of extinction. Researchers think this is why kiwi were not historically found on islands smaller than Little Barrier Island/Hauturu (3000 hectares), in the Hauraki Gulf.
The importance of genetic diversity is the reason why the different taxa of North Island brown kiwi are managed separately within our Saving the Kiwi strategy.